[Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures].

OBJECTIVE: To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF). METHODS: A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists. RESULTS: The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001). CONCLUSION: Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.

[Category of facial symmetry perception after maxillary reconstruction using anterolateral thigh flap].

OBJECTIVE: To preliminarily establish a category of facial symmetry perception after maxillary reconstruction using anterolateral thigh flap (ALTF) by the methods of stereophotogrammetry and subjective assessment. METHODS: The patients underwent maxillectomy due to neoplasms invasion, and all the maxillary defects were reconstructed using ALTF.Three-dimensional (3D) photographs were captured from the patients with a stereophotogrammatrical camera set-up.In the Geomagic software, the mirror image was created by reflecting along an arbitrary plane outside of the face.After the registration, the postoperative side on the original 3D photograph was segmented into 6 areas.The 3D change of the facial soft-tissue was measured using surface-based color map.Twenty laypeople took part in the study as observers, and they were asked to rate the 3D photographs using 5 point Likert-type scale according to their own aesthetic standard.The soft tissue asymmetry was graded according to the score.The collected data were subjected to statistical analysis using the SPSS 24.0 software. RESULTS: In the study, 44 subjects were recruited (21 males and 23 females, age range from 19 to 79 years).The soft-tissue symmetry was graded into three levels according to the subjective scores.The grade Ⅰ was basically symmetrical.The grade Ⅱ was slightly asymmetrical.The grade Ⅲ was obviously asymmetrical.Statistically significant differences were found in the suborbital (P < 0.05) and zygomatic (P < 0.05) areas when comparing all grades of soft-tissue asymmetry, and in the buccal (P < 0.05) and superiolabial (P < 0.05) areas when comparing grades Ⅰ and Ⅲ.The extent of maxillary defect had significant impact on the symmetry of the midface soft-tissue after maxillary reconstruction. CONCLUSION: Varying extent maxillectomy would result in varying degrees of asymmetry, and cause different grades of symmetry perception even if they had been reconstructed using ALTF.The higher the grade, the worse the symmetry of facial soft-tissue.Suborbital and zygomatic areas were important aesthetic units that affected the facial symmetry perception, followed by buccal and superiolabial areas.The clinicians should pay attention to the soft-tissue support in these areas when reconstructing the maxillary defect, especially large defect with orbital floor involved.

[Clinical factors affecting the prognosis of lower gingival squamous cell carcinoma].

OBJECTIVE: To define the clinical factors that influence local recurrence and survival in patients with lower gingival squamous cell carcinoma (LGSCC) and determine whether bone invasion is an independent prognostic factor for them. METHODS: A total of 104 patients with LGSCC hospitalized in Peking University Stomatology Hospital from June 2013 to December 2015 were enrolled in this retrospective study.All the patients were followed-up for more than 3 years.The degree of bone invasion was assessed using preoperative imaging data (CT and panoramic radiograph).The degree of bone invasion was divi-ded into four categories: no bone invasion, invasion of cortical bone, invasion of bone marrow cavity, and invasion of the mandibular canal.According to the central position of tumor, it was divided into two types: anterior mandibular invasion (anterior region of the mental foramen) and posterior mandibular invasion (posterior region of the mental foramen). RESULTS: of different invasion depth groups were compared using Mann-Whitney U test.P value < 0.05 was considered to be statistically significant.Kaplan-Meier survival analysis method was used to draw survival curve, and COX regression was used to explore the risk ratio (HR) and 95% confidence interval (CI) of prognostic factors of LGSCC. RESULTS: The follow-up results showed that the 1-, 3-, and 5-year survival rates of LGSCC in this group were 91%, 84%, 82%, respectively.32.7%(34/104) of patients had cervical lymph node metastasis.The cervical lymph node metastasis rate of the anterior segment of the mandible was 12.5%(2/16), and 36.4%(32/88) for the posterior segment of the mandible (P < 0.05).Univariate and multivariate COX analysis showed that the N stage and local recurrence were the prognostic factors of LGSCC patients (P < 0.05). CONCLUSION: As the degree of mandibular invasion increases, the prognosis of patients with mandibular gum cancer becomes worse.N stage and local recurrence are prognostic risk factors for LGSCC.The incidence of cervical lymph node metastasis for LGSCC is related to the primary tumor location.It is concluded that tumors located at the posterior of the mandible might be more prone to cervical lymph node metastasis than the anterior of the mandible.Thus various levels of cervical lymph node dissection strategies should be adopted for different sites of LGSCC.

[Analysis of pathological characteristics of medication-related osteonecrosis of the jaw and discussion of clinical treatment strategies based on the pathological analysis results].

OBJECTIVE: To summarize the pathological characteristics of medication-related osteonecrosis of the jaw (MRONJ) specimens after jaw curettage or jaw osteotomy treatment and to comprehensively analyze the relationship between the different pathological features, treatment methods, and treatment effects to provide new ideas for effective treatment of MRONJ in clinical work. METHODS: The clinical and pathological data were collected from 23 patients with MRONJ who were treated with curettage (18 patients) and jaw osteotomy (5 patients) at the Department of Oral and Maxillofacial Surgery of Peking University Hospital of Stomatology between June 2014 and December 2015. The pathological characteristics of MRONJ were summarized and analyzed with treatment effects based on various surgical treatment methods. The diagnostic criteria and disease staging of MRONJ were determined according to the 2014 American Association of Oral and Maxillofacial Surgeon's Position Paper. RESULTS: In this study, 5 patients have treated with jaw segmental osteotomy, and all of them were in stage Ⅲ; the other 18 patients were treated with jaw curettage, including 5 patients in stage Ⅱ and 13 patients in stage Ⅲ. The pathological features of MRONJ in five cases of jaw segmental osteotomy were divided into three adjacent regions from shallow to deep: inflammation region (IR), sclerosis region (SR), and bone remodeling layer (BRL). Moreover, three types of pathological features of specimens from traditional curettage were defined as type 1 (IR), type 2 (IR + SR), and type 3 (IR + SR + BRL). The pathological features of the patients treated with jaw curettage were: type Ⅰ, 38.9% (7/18); type Ⅱ, 44.4% (8/18); type Ⅲ, 16.7% (3/18). Complete healing was achieved in 5 patients treated with jaw segmental osteo-tomy. Moreover, 2 cases with type Ⅰ, 1 case with type Ⅱ, and 1 with type Ⅲ completely healed after jaw curettage, while 5 cases with type Ⅰ, 7 cases with type Ⅱ, and 2 cases with type Ⅲ experienced recurrence after surgery. CONCLUSION: Pathological features of continuous regions of inflammation, sclerosis, and bone remodeling layer were identified from shallow to deep, based on the microscopic observation of jaw segmental osteotomy samples. Insufficient removal of the sclerotic region during jaw curettage that blocks the required blood, nutritional factors, and mesenchymal stem cells seems to be a common cause for failed treatment of MRONJ after curettage surgery.

[Clinicopathological analysis of 105 patients with fibrous dysplasia of cranio-maxillofacial region].

OBJECTIVE: To compare the clinicopathologic features and prognosis of the different types of fibrous dysplasia (FD) of cranio-maxillofacial region, so as to provide a new reference for clinicians to treat these patients and make prognostic judgement. METHODS: Clinical records, radiographic data and pathological information of 105 patients diagnosed with FD or McCune-Albright syndrome (MAS) at the Department of Oral Pathology, Peking University Hospital of Stomatology from January 2013 to December 2020 were collected. The patients were divided into 4 groups: monostotic FDs, polyostotic FDs, MAS and a specific type called craniofacial fibrous dysplasia (CFD) limited in the craniofacial region. The clinicopathological characteristics, treatment and follow-up data of each type were analyzed. RESULTS: Of all the 105 patients, 46 were males and 59 were females, with a male-to-female ratio of 1 ∶1.3. The onset age ranged from 0 to 56 years and the median age was 12 years. On the basis of different involvement conditions, 4 types were divided. The most common type was monostotic FDs (43 cases, 40.95%), including maxilla (29 cases), mandibular (12 cases) and zygoma (2 cases). 32 cases (30.48%) were diagnosed with polyostotic FDs, 7 cases (6.67%) were MAS, and 23 cases (21.90%) were CFDs confirmed by computed tomography (CT) analysis. CFD was clearly distinct from other types of FD, such as the patient gender and the serum alkaline phosphatase level in peripheral blood before operative surgery. The pathologic findings of various types FD were quite similar, whilst the predominant fibrous tissue hyperplasia could be observed in polyostotic FDs and MAS types. CONCLUSION: The clinicopathologic features of FD in the cranio-maxillofacial region are different from the FD lesions in other parts of the body. The clinicopathological features of CFD are significantly different from those of monostotic and polyostotic FDs in the cranio-maxillofacial region. Therefore, the clinicians should pay attention to distinguish CFD in clinic, imaging and pathology aspects, so as to further clarify its features in clinic management and prognosis.

Initiation and progression of dental-stimulated temporomandibular joints osteoarthritis.

Temporomandibular joint (TMJ), a site that is often impacted by osteoarthritis (OA), is biomechanically linked with dental occlusion. Tissue responses in TMJ condyle to biomechanical stimulation could be investigated by intervention of the dental occlusion in animals. Unilateral anterior crossbite, an experimental malocclusion, has been demonstrated to induce TMJ-OA lesions, showing primarily as enhanced cartilage calcification and subchondral cortical bone formation at the osteochondral interface, causing the osteochondral interface thickening and stiffening. The changed interface would worsen the local biomechanical environment. At the cartilage side, the matrix degenerates. In the case of insufficient restoration of the matrix, the cells in the deep zone flow into the ones undergoing autophagy, apoptosis, and terminal differentiation while the cells in the superficial zone are promoted to differentiate to supply the loss of the deep zone cells. At the meantime, the bone marrow stromal cells are stimulated to bone formation in the subchondral cortical region which is uncoupled with the sites of the osteoclast-mediated resorption process that is predominantly observed at the subchondral trabecular bone region. Overall, the thickening and stiffening osteochondral interface, due greatly to the enhanced endochondral ossification in deep zone cartilage, should be a central pathological process that links with cartilage decay and subchondral bone remodelling in OA joints. The residual chondrocytes locating in the cartilage superficial zone have the progenitor-like qualities that can proliferate, and also differentiate into the deep zone chondrocytes, thus should be critical in progression and rehabilitation of TMJ-OA.

[Study of cytokines in peripheral blood and lung of rats exposed to hard metal dust].

Objective: To study the dynamic changes of cytokines in bronchoalveolar lavage fluid (BALF) and serum of hard metal lung disease (HMLDR) rats. Methods: In March 2019, the rats were randomly divided into 6 groups, each group included 8 rats: control (C) group include 3 groups, hard metal (HM) group include 3 groups. 10 mg HM were administered in HM group by using the pulmonary endotracheal tube. After 4, 8 and 12 week, the BALF and serum were collected for the enzyme-linked immunosorbent assay (ELISA) of matrix metalloproteinase-1 (MMP-1) , tissue inhibitor of metalloproteinase-1 (TIMP-1) and tumor necrosis factor-alpha (TNF-α) . Results: There was no abnormality in behavior, diet and fur of rats in C and HM group at each exposure time. There was no significant difference in body weight between the two groups of rats (P>0.05) . Compared with the C group, the expression of MMP-1 in BALF of rats in HM group were significantly higher in all stages (4, 8 and 12 weeks after exposure) (P<0.05) , the expression of TIMP-1 in BALF of rats in HM group were significantly higher in 8 and 12 weeks after exposure (P<0.05) . However, there was no significant difference in serum MMP-1 and TIMP-1 levels between the two groups in each stage (P>0.05) . There was no significant difference in TNF-α. level in BALF and serum between C and HM group in all stages (P>0.05) . Conclusion: Expression of MMP-1 and TIMP-1 in BALF have reference value in the HMLD auxiliary diagnosis.

In vivo anti-ageing activity of cream containing niosomes loaded with purple glutinous rice (Oryza sativa Linn.) extract.

OBJECTIVE: To evaluate the anti-ageing activity of cream containing the methanolic purple glutinous rice extract loaded in niosomes. METHODS: The in vitro biological activities of the purple glutinous rice extracted by methanol maceration were determined. The extract loaded in niosomes and the cream containing the niosomes were developed. The in vivo anti-ageing activity in 20 human volunteers including skin hydration, pigmentation, roughness and elasticity after daily application for 28 days compared to at initial was evaluated by Corneometer, Mexameter, Visiometer and Cutometer, respectively. RESULTS: The purple glutinous rice extract showed free radical scavenging (SC50 ), lipid peroxidation inhibition (IPC50 ), metal ion chelating (CC50 ) and tyrosinase inhibition (IC50 ) values at 32.31 ± 1.28, 57.40 ± 2.12, 85.05 ± 5.43 and 43.89 ± 2.14 mg/mL which were 0.00031, 0.011, 0.0078 and 0.0016 times of the standards (0.01 ± 0.00, 0.62 ± 0.14, 0.66 ± 0.05 and 0.07 ± 0.01), respectively. The purple glutinous rice extract contained 0.35 µg of anthocyanin/1 mg of the extract determined by HPLC. After loaded in niosomes, the solubility of the extract was not only increased in various solvents, but also the chemical stability in different environments (weak base, reducing agent and acid salt) was improved. The cream formulation containing niosomes loaded with 1%w/v of the purple glutinous rice extract indicated the anthocyanin remaining percentages after 6 cycles of heating and cooling test at 52.28% of the initial. For in vivo anti-ageing activities, cream containing niosomes loaded with the extract gave significant decreased melanin index and skin roughness reduction of -14.05 and -9.95% of the initial, respectively. The % changes of the increased skin hydration, skin elastic extension and skin elastic recovery when applied on human volunteers' skin with this formulation were +48.73, -24.51 and +35.98%, respectively. CONCLUSION: The cream containing niosomes loaded with the 1%w/v methanolic purple glutinous rice extract gave not only the suitable in vitro antioxidant activity and physical stability of the active anthocyanin, but also the superior in vivo anti-ageing activity on human skin compared to the cream base and before application which can be further developed as a novel anti-ageing cosmeceutical product.

OBJECTIF: Evaluer l'activité anti-âge d'une crème contenant de l'extrait de riz gluant violet méthanolique chargé en niosomes. MÉTHODES: Les activités biologiques in vitro de l'extrait du riz gluant violet par macération au méthanol ont été déterminées. L'extrait chargé en niosomes et la crème contenant les niosomes ont été développés. L'activité anti-âge in vivo sur 20 volontaires humains, y compris de l'hydratation de la peau, la pigmentation, la rugosité et l'élasticité après une application quotidienne pendant 28 jours a été évaluée par comparaison avec T0 par cornéomètre, mexamètre, visiomètre et cutomètre, respectivement. RÉSULTATS: L'extrait de riz gluant violet a montré des valeurs de piégeage des radicaux libres (SC50), d'inhibition de la peroxydation lipidique (IPC50), de chélation des ions métalliques (CC50) et d'inhibition de la tyrosinase (IC50) à 32,31 ± 1,28, 57,40 ± 2,12, 85,05 ± 5,43 et 43,89 ± 2,14 mg / ml qui étaient 0,00031, 0,011, 0,0078 et 0,0016 fois des standards respectivement (0,01 ± 0,00, 0,62 ± 0,14, 0,66 ± 0,05 et 0,07 ± 0,01). L'extrait de riz gluant violet contenait 0.35 pg d'anthocyanine / 1 mg de l'extrait déterminé par HPLC. Après avoir été chargé dans les niosomes, la solubilité de l'extrait a non seulement été augmentée dans divers solvants, mais aussi la stabilité chimique dans différents environnements (base faible, agent réducteur et sel d'acide) a été améliorée. La formulation de crème contenant des niosomes chargés avec 1% p / v de l'extrait de riz gluant violet a indiqué les pourcentages d'anthocyanine restants après 6 cycles de test de chauffage et de refroidissement à 52,28% de la valeur initiale. Pour les activités anti-âge in vivo, la crème contenant des niosomes chargés de l'extrait a donné une réduction significative de l'indice de mélanine et de la rugosité cutanée de -14,05 et -9,95% de la valeur initiale, respectivement. Les pourcentages de variation de l'hydratation accrue de la peau, de l'extension élastique de la peau et de la récupération de l'élasticité de la peau lors de l'application sur la peau de volontaires humains avec cette formulation étaient respectivement de +48,73, -24,51 et + 35,98%. CONCLUSION: La crème contenant des niosomes chargée avec l'extrait de riz gluant violet méthanolique à 1% p / v a donné non seulement une activité antioxydante in vitro appropriée et une stabilité physique de l'anthocyanine active, mais également une activité anti-vieillissement in vivo supérieure sur la peau humaine par rapport à la base de la crème et avant application, qui peut être développée en tant que nouveau produit cosméceutique anti-âge. Mots clés: riz gluant violet, niosomes, antioxydant, inhibition de la tyrosinase, efficacité anti-âge in vivo, produit cosméceutique.

[wareness and knowledge of oral cancer among 1 483 residents in Beijing].

OBJECTIVE: To investigate the oral cancer awareness, its related knowledge among residents in Beijing. METHODS: A questionnaire survey was conducted among Beijing residents (non-medical related personnel) on the knowledge of oral cancer and its prevention and treatment. RESULTS: A total of 1 483 questionnaires were completed, including 663 males (44.6%) and 820 females (55.3%), ranging from 15 to 91 years. Lung cancer was the most mentioned as heard of (94.3%), followed by liver cancer (92.5%) and gastric cancer (92.4%), while oral cancer was the least heard of (47.7%). Family account (P=0.015), residence (P=0.028), income (P=0.024), frequency of brushing teeth (P<0.001), frequency of mouth self-examination (P<0.001) and chew betel nut chewing (P=0.015) were significantly associated with oral cancer awareness. Most respondents learned about oral cancer from TV programs (24.3%), phone news (22.0%), WeChat (11.3%) and chatting with friends or people around (14.6%). Only 34.9% knew that smoking was a risk factor of oral cancer, and this knowledge was associated with age (P=0.011), education level (P=0.007), frequency of brushing teeth (P<0.001), and frequency of mouth self-examination (P=0.002). Only 23.5% knew that drinking was a risk factor of oral cancer, and this knowledge was associated with education level (P=0.002), residence (P=0.022), frequency of brushing teeth (P=0.009), and frequency of mouth self-examination (P=0.005). Only 35.1% knew that betel nut chewing was a risk factor for oral cancer, and this knowledge was associated with age (P=0.040), education level (P=0.002), family account (P=0.002), income (P=0.005), frequency of brushing teeth (P=0.001), frequency of mouth self-examination (P<0.001), and betel nut chewing (P=0.002). Only 35.7%, 21.6% and 16.9%, respectively, knew that long-term unhealed ulcers, white plaques and red plaques in the mouth were the early signs of oral cancer. CONCLUSION: This survey demonstrates a general lack of public awareness and knowledge about signs and symptoms of oral cancer, and its risk factors and treatment. Some residents have not formed good oral hygiene habits. Specific measures should be taken to improve the public awareness of oral cancer and related knowledge about prevention and treatment, such as the use of various new media for the public to promote their oral health knowledge, in order to reduce the incidence of oral cancer, improve early attendance rates and the patients' survival rates.

[Predictive values of the combination of Friedman stage and sleep oximetry done early after surgery in predicting the treatment outcomes of uvulopalatopharyngoplasty].

OBJECTIVE: To explore the predictive values of the combination of preoperative data, including medical history and physical examination, and results of sleep oximetry performed early after the surgery (one week) in predicting the treatment outcomes of uvulopalatopharyngoplasty (UPPP) in adult patients with obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: All the patients who were diagnosed with OSAHS, underwent UPPP treatment and had complete follow-up data in our institution between Jan 2013 and May 2016 were enrolled in our study. The pre-operative data of these patients, including age, physical examination, and polysomnography (PSG) data, were all exactly collected for analysis. All these patients had received the evaluation of subjective efficacy scale and the sleep oximetry test in early post-operative days (within one week). The long-term efficacy evaluations including PSG and subjective efficacy scale were all finished at least three months after the surgery. RESULTS: In the research 61 patients were finally studied, including 25 responders (41.0%) and 36 non-responders (59.0%). Regression analysis revealed that the pre-operative Friedman stage and early post-operative oxygen desaturation index of ≥4% (ODI4) were found to be independently predictive parameters for the UPPP treatment outcomes (P<0.05). The ROC curve analysis was used to estimate the predictive values of ODI4 to the treatment outcomes, and it was calculated with an area under the curve of 0.822. Using the ODI4 of 15 as the cutoff value, the sensitivity and specificity of that calculated were up to 0.778 and 0.760 respectively. The response rate among the patients with an early post-operative ODI4 of <15 was 70.4%, which was significantly higher than that of the patients with an early post-operative ODI4 of ≥15, whose response rate was 17.6% (P<0.05). The similar results could also be obtained in the patients with pre-operative Friedman stage II (87.5% vs.25.0%) and Friedman stage III (33.3% vs. 6.7%). CONCLUSION: The combination of early post UPPP operation oximetry parameters, especially ODI4, and pre-operative Friedman stage could be used in better evaluating the potential surgical outcomes of UPPP.

[Preliminary evaluation of a virtual reality dental simulation system on training of caries identification ability].

OBJECTIVE: To develop a software based on "UniDental" system which is a virtual reality dental simulation system and applied to undergraduate majoring in stomatology to improve the ability of identifying caries. METHODS: A software was developed applying to identify virtual dental caries based on UniDental system. In the software, a virtual dental caries model was designed and carious tissue was separated to 3 layers by the depth. The stiffness was the same within each layer which was increasing gradually layer by layer. The roughness was also the same within each layer which was decreasing gradually layer by layer. Sixty-four participants in pre-clinical stage of the class of 2014 majoring in stomatology from Peking University School of Stomatology were trained with the software. During the training, the students should probe on the virtual dental carious tissue layer by layer and feel the difference of vertical stiffness and horizontal roughness of each layer by using a handpiece with realistic force feedback. After training, a questionnaire survey was conducted to evaluate the software including a score of 1-5 for haptic fidelity of stiffness and roughness and their relevant gradient and benefit of improving the ability of identifying caries, choosing the preferred training method. The data were statistically analyzed using Kruskal-Wallis test. RESULTS: The median of subjective evaluation scores of the proposed metrics were all "4", demonstrating that the software operated above medium fidelity. The stiffness scores of all 3 layers were statistically significant (P < 0.05) on the stiffness gradient score. The roughness scores of the 1st and 2nd layers were statistically significant (P < 0.05) on the roughness gradient score. The training was helpful to improve the ability of identifying caries (median was 4). The scores of all 3 layers stiffness and relevant gradient were statistically significant (P < 0.05) on the score of benefit of improving the ability of identifying caries. 90.4% of the participants preferred the traditional extracted teeth training method. CONCLUSION: The virtual reality dental simulation system was helpful to improve students' ability of identifying caries. It couldn't replace the traditional extracted teeth training method by now, it should be used as a supplement to the traditional training method.

[Clinicopathological analysis of 844 cases of odontogenic keratocysts].

OBJECTIVE: To investigate the clinicopathologic features and prognostic factors in odontogenic keratocyst (OKC), and to provide new reference for clinic treatment and management of these patients. METHODS: Clinicopathological data of 844 cases initially diagnosed as or associated with OKC at Department of Oral Pathology, Peking University Hospital of Stomatology from 2000 to 2018 were collected. The cases were divided into 4 groups: sporadic OKCs (intraosseous, cystic lesion irrelevant to nevoid basal cell carcinoma syndrome), syndromic OKCs, solid OKCs and peripheral OKCs. The patients were follow-up for 6 to 216 months and the factors that might relate to recurrence were analyzed. RESULTS: There were 805 cases (95.4%) of sporadic OKCs, 32 cases (3.8%) of syndromic OKCs, 3 cases of solid OKCs and 4 cases of peripheral OKCs. The main age of sporadic OKCs was 36.03 years with the peak at the second and third decades. Ratio of male and female was 1.27:1. The predilection site was the molar and ramus area of mandibular (56.2%). In the study, 428 cases (71.2%) were unilocular in radiography while 28.8% were multilocular. The recurrent rate of enucleation with the follow-up was 20.1% (118/588) while most of them occurred in 1-3 years after surgery. The recurrent rate of multilocular patients (39.0%) was significantly higher than that of the unilocular. Enucleation after marsupialization (43 cases) or enucleation only (545 cases) showed no difference in recurrence (P>0.05). The syndromic OKCs was younger (main 20.97) and preferred to be multiple compared with sporadic OKCs (30/32, 93.7%). The predilection site was also molar and ramus area of mandibular (41.7%). Age and gender distribution of multiple cases had no significant difference with those in sporadic OKCs. More daughter cysts and epithelial islands were seen (56.3% and 17.9%). Furthermore, the recurrent rate was significantly higher than that of the sporadic OKCs (13/29, 44.9%). But there was no evidence of recurrent-related factors. The age of solid and peripheral OKCs, averaged at 45.00 and 65.75 years, were older than others. Four of peripheral OKCs showed no recurrence after enucleation. CONCLUSION: The recurrence rate of sporadic OKCs after enucleation is 20.1%. The multilocular lesions prefer to be recurrent. There is no significant difference of recurrence with enucleation only or enucleation after marsupialization. Compared with sporadic OKCs, the syndromic patients are younger and easier to be multiple. It tends to be recurrent frequently and rapidly. There are no related factors about recurrence of syndromic patients. The clinicians should considerate comprehensively and make an individual management of therapy and follow-up. Solid and peripheral OKCs are rare and older.

[Application and exploration of Smile Lite MDP portable photography system in aesthetic photography of anterior teeth].

OBJECTIVE: To explore the possibility of the Smile Lite MDP (Smile Lite Mobile Dental Photograph) portable dental photography system applying in anterior teeth aesthetic photography, and to provide the chance to simplify aesthetic photography process and facilitate communication among patients, dentists and dental technitians. METHODS: The Smile Lite MDP photography system combined with the smartphone were used to photograph the front occlusal phase photos of anterior teeth. The photographic conditions including the color temperature parameter, the Smile Lite MDP light position and the intensity settings were explored. The best photographic conditions were chosen by blind evaluation within experienced dentists and technicians through the method of the visual analogue scale/score (VAS) evaluation, which went through statistical analysis to figure out the optimum photograghic conditions. Smile Lite MDP photography system was used to photograph the front occlusal phase photos of anterior teeth under the optimum parameter by different magnifications. The width/height ratio of the central incisor and the front width ratio of the upper anterior teeth in those photos were measured and calculated respectively. The accuracy of the anterior teeth photos taken by Smile Lite MDP photography system was analyzed based on the photographs taken by digital single lens reflex (DSLR) camera. RESULTS: The optimum color temperature parameter of Smile Lite MDP portable camera system was 5 000 K, the optimum magnification was 4 times, the best light position was the side lights of Smile Lite MDP, the optimum intensity of lights was 2 grades. Photos taken by the optimum parameters won the highest score during the VAS evaluation and the result of statistical analysis had significant difference compared with other groups (P<0.05). When comparing the photos of the upper anterior teeth taken by the Smile Lite MDP portable photography system using 4 times magnification or by DSLR using the standard parameters, there was no significant difference neither in the width/hieght ratio of the central incisor nor in the front width ratio of the upper anterior teeth (P>0.05). CONCLUSION: The Smile Lite MDP portable dental photography system applying in anterior teeth aesthetic analysis photography was capable to show the color and shape of anterior teeth in an accurate way by using the right photography parameters. Therefore, Smile Lite MDP portable dental photography system was considered to be a simple and easy photographic tool in clinical work.

[Blood-borne occupation exposures in dental practice of medical staff: status and protection].

Objective: To understand the status of blood-borne occupational exposure and protection among health care workers (HCWs) in dental practice, and provide evidence for making effective prevention. Methods: From April 1 to 15, 2019, a stratified random sampling method was conducted to investigate the data of blood-borne occupational exposure among 221 dental HCWs in 2018, and Chi-squared Test was used to evaluate the differences of status on occupational exposure and protection among different professionals, such as nurses, doctors and trainees, and among different-grade hospitals. Results: A total of 166 HCWs were exposed to occupational exposure 269 times, with the annual incidence of 75.11% (166/221) , and 37.55% (101/269) of exposures were reported. However, all source patients of exposures had failed to be traced. 89.59% (241/269) of exposures were sharp injuries. The top three instruments caused injuries were syringe/bilan needles, suture needles and vehicle needles, accounting for 35.68% (86/241) 、16.60% (40/241) and 16.18% (39/241) , respectively; and the top three exposure operations were removal/disposal of needles or instruments, suture/assisting suture and injection of anesthetic, accounting for 37.17% (100/269) 、22.30% (60/269) and 17.84% (48/269) , respectively. There were statistically significant differences among different professionals in occupational exposure frequency, reporting rate, the types of instruments caused injuries, exposure operations and hepatitis B vaccinated time (P<0.01) . The compliance rate of standard precautions, safe operation, post-exposure reporting and prevention, and training on occupational protection were generally poor among HCWs, with significant differences in different-grade hospitals (P<0.01) . Conclusion: There is a high incidence, low reporting rate and poor self-protection of blood-borne occupational exposure among dental HCWs. Strongly suggesting that standard precautions, safe use and disposal of oral instruments, active post-exposure report and prevention must be improved for everyone.

Transarterial embolisation with bleomycin and N-butyl-2-cyanoacrylate -Lipiodol mixture for symptomatic polycystic liver disease: preliminary experience.

AIMS: To evaluate the therapeutic effect and safety of transarterial embolisation using a bleomycin-Lipiodol mixture and N-butyl-2-cyanoacrylate (NBCA)-Lipiodol mixture (BNL) for the treatment of polycystic liver disease (PLD). MATERIALS AND METHODS: From June 2012 to July 2018, a total of consecutive 14 symptomatic patients (13 women and 1 man; mean age, 49.3±9.9 years) with PLD were referred and underwent transcatheter arterial embolisation (TAE) with BNL. RESULTS: Technical success was achieved in all cases. PLD-related severe symptoms were improved remarkably in 13 of the treated patients. The mean maximum abdominal circumference decreased significantly from 100.6±9.4 to 94.9±9.1 cm (p<0.01). The total liver volume decreased significantly compared with pre-TAE in 13 patients at 6-12 months after TAE. It decreased from 9,776±2,219 to 8,303±2,009 cm3 (p<0.01). There were no major complications associated with the procedure. CONCLUSION: TAE with the bleomycin-Lipiodol mixture and NBCA-Lipiodol mixture may be an effective method for treating symptomatic PLD patients, with improvement of symptoms and shrinkage of cyst volume.

[Computed tomographic features of desmoplastic ameloblastoma of the jaw].

OBJECTIVE: To retrospectively analyze the clinical and CT imaging features of desmoplastic ameloblastomas (DA) in comparison with other types of ameloblastomas. METHODS: Patients diagnosed with ameloblastoma histopathologically in Peking University School and Hospital of Stomatology from July 2000 to August 2017 were reviewed to analyze the constituent ratios and characteristics of DA. CT imaging features of DA (28 cases) were investigated in comparison with consecutive cases of solid/multicystic and unicystic ameloblastomas. The following imaging perspectives were analyzed: the border, internal structure, three-dimensional shape, tooth, the periodontium, the cortex and the expansion of the tumors. CT values were measured in the region of interest for quantitative analysis. RESULTS: Among the 1 269 cases of ameloblastomas, 50 (3.9%) were DA, which showed predilections for males (74.0%). The average age of DA was about 43.9 years old, which was higher than the other two types. The anterior incisorcanine region (62.0%) and premolar region (30.0%) were most frequently affected. The incidence rate of DA in mandibule was 56.0% (28/50), which was slightly higher than that of maxilla (44.0%). The DA characteristically showed scallop border and honeycomblike or soapbubble internal structure with bone formation on CT. The mean ratios of height to mesiodistal and buccal-lingual to mesio-distal distances were 0.76 and 0.63, which were higher than the other two types. According to the degree of internal bone formation, three subtypes of DA could be observed: densely ossifying type (I), honeycomb/soap bubble type (II) and sparsely ossifying type (III). The means and standard deviations of CT values of DA were significantly higher than those of the other two types, which were (488.8±164.0) HU (type I), (171.7±102.8) HU (type II), (42.1±8.8) HU (type III). CONCLUSION: CT is helpful for diagnosis of DA, which shows as solid tumor with varying degrees of internal ossification.

[BRAF gene mutations in ameloblastic fibromas].

OBJECTIVE: To investigate the BRAF gene mutations in ameloblastic fibroma (AF), and to further analyze the relationship between the BRAF mutation and clinical characteristics so as to provide new reference to the study of AF's molecular pathology. METHODS: Sixteen cases diagnosed as AF at the Department of Oral Pathology, Peking University School of Stomatology between January 1990 and December 2017 were collected. Genomic DNA was extracted from formalin-fixed, paraffin embedded tissues using the QIAamp DNA Mini Kit (Qiagen, Germany) according to the manufacturer's instructions. Polymerase chain reaction (PCR) and direct sequencings were used to detect the BRAF gene mutations. The clinicopathological data, such as the age, location of the lesion, symptoms and treatments were retrospectively analyzed. RESULTS: The sixteen cases of AF involved nine women and seven men aged 2-67 years. Three lesions occurred in the maxilla and thirteen in the mandible. The most common presenting symptom of AF was a painless slowly enlarging mass with swelling. Ten patients received conservative treatment and the other six patients received radical surgery. Three cases relapsed during the study period. BRAF gene mutation was found in sixteen of all the sixteen samples analyzed (100%). The BRAF mutation was a point mutation with a thymine-adenine transversion at nucleotide 1 799 of 15 exons, resulting in a change at residue 600 that substituted glutamine for valine. This mutation was the strongest activator of the downstream RAS/RAF/MEK/ERK-MAPK signaling pathway. This helped to bring about a gain-of-function mutation due to a V600E substitution. Many studies identified that BRAF regulated survival, apoptosis, and proliferation of cells by inducing MAPK pathways activation. For the existing cases, none of the age, sex, location, recurrence and treatments had a statistically significant correlation with BRAF mutation. CONCLUSION: Our findings demonstrated high prevalence of BRAF V600E mutation in AF. The pathogenic role remains to be clarified．.

The effect of antiseptic oral sprays on dental plaque and gingival inflammation: A systematic review and meta-analysis.

OBJECTIVES: To review the effectiveness of antiseptic oral sprays on oral health. METHODS AND MATERIALS: Three electronic databases (PubMed, Cochrane Library and Web of Science) were systematically searched to identify relevant studies. Only randomized controlled trials (RCTs) comparing the effect of oral sprays to placebo/control spray or mouthrinse on dental plaque and gingival inflammation were included. RESULTS: Among a total of 996 papers, 20 effective studies fulfilled the selection criteria, and 8 studies were suitable for inclusion in meta-analyses. A meta-analysis of three studies using a 0.2% chlorhexidine (CHX) spray intervention, without prophylaxis at baseline, showed reductions in Plaque Index (PI) (Silness and Löe) and Gingival Index (GI) (Silness and Löe) scores of 0.74 (95% CI: -1.03 to -0.45) and 0.22 (95% CI: -0.38 to -0.06), respectively. Five studies provided a prophylaxis for subjects before study initiation. Three of these five studies used 0.2% CHX spray. A meta-analysis demonstrated an increase of 0.18 (95% CI: -0.01 to 0.37) in PI (Silness and Löe) scores. Two RCTs compared 0.12% and 0.2% CHX spray, and a meta-analysis showed increases of 1.71 (95% CI: 1.27 to 2.14) and 1.58 (95% CI: 1.23 to 1.93), respectively, in PI (Quigley and Hein) scores. Of the RCTs not amenable to meta-analysis, eight studies reported significant improvements in PI and GI scores. CONCLUSIONS: Available evidence suggests that oral sprays are an acceptable delivery method for antiseptic agents. Further high-quality studies are warranted to determine the effectiveness of alternative chemotherapeutic agents delivered via oral sprays on oral health.

[Development of ethylene glycol Samples in silicone tubes and their application in inter-laboratory comparison].

Objective: To development of ethylene glycol samples in silicone tubes, and the samples were applied to inter-laboratory comparison, through it to evaluate the detection capacity of occupational health testing laboratories. Methods: Three content levels of ethylene glycol samples in silicone tubes were prepared, and the homogeneity and stability of samples were investigated, the results were statistically analyzed. A robust statistical four-point distance method was used to calculate the results submitted by each participant laboratory and the test capability of the laboratory was assessed by the z-score method. Results: The statistic of the homogeneity of ethylene glycol samples in silicone tubes were less than the critical value (P>0.05) , and the samples were stable at room temperature for one month. The satisfactory rate of comparison between 204 laboratories was 88.24%. Conclusion: The homogeneity and stability of the ethylene glycol samples in the silicone tubes can meet the requirements of proficiency testing and can be used for laboratory comparison. Most of the laboratories that participated in the comparison had the ability to detect ethylene glycol.

Tannerella forsythia and coating color on the tongue dorsum, and fatty food liking associate with fat accumulation and insulin resistance in adult catch-up fat.

BACKGROUND/OBJECTIVES: We aimed to determine the alteration of Tannerella forsythia and coating color on the dorsal tongue, and fatty food liking in catch-up fat in adult (CUFA), as well as the probable associations between fat accumulation, insulin resistance (IR) and these changes. SUBJECTS/METHODS: T. forsythia on the tongue dorsum, fatty food liking, fat accumulation and insulin sensitivity were investigated in CUFA humans and rats, and tongue-coating color was observed in CUFA individuals. We further determined the changes of fatty food liking, fat accumulation and IR in T. forsythia-infected rodents by oral lavage. RESULTS: Increases in fat accumulation, IR, percentage of subjects with yellow tongue coating and that with T. forsythia detected were observed in CUFA individuals. Additionally, the fat ranking scores were significantly lower and the hedonic ratings of low-fat options of sampled food were lower, while the ratings of high-fat options were remarkably higher in CUFA subjects. Additionally, T. forsythia level elevated in CUFA rats, and fatty food liking, fat accumulation and IR increased in CUFA and T. forsythia-infected animals, with the increases in T. forsythia infection and fatty food liking preceding the occurrence of fat accumulation and IR. CONCLUSIONS: T. forsythia and yellow coating on the dorsal tongue and fatty food liking associate fat accumulation and IR in CUFA. Moreover, we tentatively put forward that T. forsythia, which is very important in yellow tongue-coating microbiota, and its consequent increases in fatty food liking, might be crucial in the development of fat accumulation and IR in CUFA.